Improved rock-drill



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To all whom 'it may concern JOHN M. 'WHARTNABY, Ion PHILADELPHIA, PENNSYLVANIA, AssIeNon 'ro HIMSELF AND SAMUEL P. FAUNOE, on SAME PLAGE, ASSIGNoRs To SAID WHARTNABY AND FRANcIsvsoHNnoHTnn.

`Letters Patent No. 94,854, dated September 14, 1869.

IMPRovIsD Rock-DRILL.

Be it known that I, `JonN M. WHARTNABY, of Philadelphia, Pennsylvania, have invented an Improvement in Rock-Drills; and I do hereby declare the following to be a full, clear, and exact4 description ofthe same.

My invention consists of a drill, having an inclined end and a vertical or inclined cnttingedge, as fully described hereafter, s o that on strikingthe rock the', cutting-edge will be forced' laterally toward the sides ofthe opening, thus enlarging the latter, and producing an opening of a diameter' much greater than that of. the drill at its widest part. i

In order to enable others skilled in the art to make and use my invention, I will now proceed to describe `its 4construction andoperation, reference being had to the accompanying drawing-which forms a part of this speciication, `and in which- Figure l is a side View of myv improved rock-drill; Figure 2,. an edge view, looking in the direction of l the arrow, iig. l;

Figure 3, an inverted end view;

Figure 4, a section on the line 1-2, fig. 1

Figure 5, a section on the line 3 4, iig. l; and

Figure 6, a modilication.

The stock of the drill consists of' a steel bar, A, which, in the present instance, is octagonal in its cross-section; anda-t one sideof the stock, at its lower end, isan enlargement or projection, a.

The edge of the projection a is curved from the- Stock to the most prominent portion or point as, and from the latter to a point, y, at the end s of thedrill, which is inclined downward from the heel w to the said point y, for a purpose described hereafter.

The back of the drill is slightly curved from the of' this inclination 'of its end, will be directed from its vertical course laterally, in the direction of the cutting-edge a: I lwhich is thus brought against the rock so as to chipthe sides, instead of the bottom only, ot' the opening, an opening of greater diameter than that of the'drill at its widest point being thus produced. It will be apparent that the operation of the drill will depend .upon the inclination of the end s, land of that of the cutting-edge a; y. If, for inst-ance, itis. only desired tov 'ream or enlarge anopening already bored, a drill, with a vertical or nearly vertical cnttingedge,`1nay be used, as shown in iig. 6.

Without confining myself to the precise construetion shown and described,

I claim as my invention, and desire. to secure by Letters Patent- A rock-drill, having an inclined end, and an inclined or vertical cutting-edge, substantially as and for the,v

purpose described. Y In testimony whereof, I have signed my name to this specieatiolnin the presence of two subscribing wit-' JOHN WHITE, HARRY SMITH. 

